Laumann, Kristina

Abstract Abstract 1958 Vaccines may offer additional benefit as consolidation therapy after plateau phase or autologous stem cell transplant (ASCT) for multiple myeloma (MM). We have reported previously the results of another phase II trial showing that using APC8020 (Mylovenge™) after ASCT improved the overall survival (OS 5.3 yrs, 95% CI 4.0 yrs – NA) compared to ASCT alone (3.4 yrs, 95% CI 2.7 – 4.6 yrs; p = 0.02; Lacy, AJH (84): 799). We now report the results from a randomized, phase II trial using the same vaccine plus adjuvant cytokines in MM patients in plateau phase after either chemotherapy or ASCT. Twenty patients were enrolled between 2001 and 2003 and were randomized to receive APC8020 and adjuvant cytokine of either interferon-g (IFNg, arm A, n = 10) or interleukin-2 (IL2, arm B, n = 10). Each cycle of treatment included five days of daily subcutaneous injections of either IFNg (106 IU, arm A) or IL2 (200 mg, arm B) followed by APC8020 injection. Each patient received a cycle of treatment every 2 weeks for 4 cycles. One patient in each arm was in plateau phase post-chemotherapy. Time from diagnosis to treatment was 11.9 mos for the patient in arm A and 16.2 mos for arm B. Time to progression (TTP) was 3.7 and 68 months respectively the patient in arm A and B. Both patients were alive at five years. For the 9 post-ASCT patients in each arm, no statistically significant differences were seen in the baseline characteristics between the 2 arms. The median time from diagnosis to treatment was 15.4 months. No grade 4 or 5 adverse events (AEs) were reported. Two patients in each arm had grade 3 AE, including lymphopenia, thrombocytopenia, hemorrhage, infection, and fatigue. One patient in arm B had grade 3 autoimmune disorder that was deemed possibly related to study treatment. The most common AEs were grade 1 fatigue (n = 7) and anemia (n = 5) in arm A and grade 1 anemia (n = 7) and injection site reaction (n = 5) in arm B. The median TTP was 9.3 months (95% CI: 3.9 – 19.3 months) for arm A and 6.6 months for arm B (95% CI: 6.3 – 29.6 months) with no statistically significant difference between the two arms (p = 0.89). The median OS had not been reached for either arm; the 5-year OS rate was 67% and 56% for arms A and B respectively (p = 1.0). Interestingly, similar to our previous study where TTP was not different while OS was improved with vaccine, when we compared the clinical outcome for all patients in this vaccine trial to that of 78 matched control patients who only received ASCT during the same time frame, we did not see significant improvement in TTP (Figure 1). However, the 5-year overall survival for all patients in this trial is significantly improved at 71% (95%CI: 51–96%) compared to ASCT control patients (41%, 95% CI: 31 – 54%; p = 0.03; Figure 1). This trial suggests improved OS with vaccine plus cytokine. It is possible that modulation of patients’ immunity may help them live longer with multiple myeloma. Further investigation is needed to compare the approach in this trial with dendritic cell vaccine alone to better understand optimal strategy for vaccine therapy in MM. Figure 1. Kaplan-Meier curves for time to progression and overall survival Figure 1. Kaplan-Meier curves for time to progression and overall survival Disclosures: Dispenzieri: Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Lacy:Celgene: Research Funding.

Abstract Background: Dexamethasone (dex) is an integral part of various anti-myeloma regimens both in the frontline and relapsed/refractory (RR) setting. Several clinical trials have shown that dex adds to the efficacy of novel therapeutic agents for multiple myeloma (MM). Yet, a substantial number of patients are intolerant to even the standard of care low-dose dex (40 mg weekly), especially in heavily pre-treated RRMM, possibly due to cumulative steroid toxicities and thus, require dex dose adjustments. There is a concern of compromising the efficacy of anti-MM regimens by adjusting the dex dose lower. We describe the frequency of dex dose adjustment, characteristics of patients who required it and its effect on patient outcomes in a large prospective clinical trial of pomalidomide (pom) and dex in RRMM (MC0789). Methods: We utilized data from the Pom-dex trial (MC0789), which treated RRMM patients in different cohorts of pom (2 vs. 4 mg; 21 vs 28 days cycle) with fixed dose dex (40 mg orally weekly). Patients were divided into 2 subgroups, with any dose adjustment/elimination of dex vs. not. Continuous and categorical variables were compared between the two groups using two-sample t-test/Wilcoxon rank sum test or Chi-squared test, respectively. Logistic regression and Cox regression models were used to find the univariate and stepwise multivariate predictors of response to treatment and overall mortality, respectively. Kaplan-Meier method was used to estimate overall survival (OS) at 1, 3, and 5 years. All statistical tests were two-sided with the alpha level set at 0.05 for statistical significance. Results: Results from the MC0789 clinical trial have been reported previously. Almost half of all treated patients in this trial had dex dose adjusted (n=175/343; 51%). The median number of cycles for the first dose adjustment in this group was 3 (range 1-62), with 46.5% of patients (n=82) having multiple dose adjustments and majority (58.3%, n=102) within the first 3 cycles of treatment. Patients in the dose adjustment group were significantly older (mean 65 vs 60 years; p=0.0001). Males, Whites and patients diagnosed before 2006 or with normal cytogenetics also had a higher incidence of dex dose adjustment, though this was not statistically significant. Patients with dex dose adjustment had a longer duration of treatment (mean 339 days) as compared to the non-adjusted cohort (mean 123.65 days) (95% CI 160.13, 270.58; p <0.0001). Dex dose adjustment was associated with a higher probability of responding in the clinical trial after a univariate (p<0.001) as well as multivariate (p<0.001) analysis. Patients with dex dose adjustment also had a significantly better OS at 1, 3 and 5 years by univariate (p<0.001) and multivariate (p<0.001) analysis. (Figure 1) The only other significant factor was lesser number of prior regimens (3 or less), associated with a higher probability of response (p=0.002) and survival (p<0.001). Conclusion: Our analysis established that in these heavily pre-treated RRMM patients, appropriate dose adjustment of dex did not compromise their response rates; patients remained on treatment significantly longer and had an improved survival. Majority of patients (58.3%) requiring dex dose adjustment had it instituted early during treatment (<3 cycles), suggesting that early disease progression was less likely to determine dex dose continuation or adjustment. Appropriate dex adjustments should be judiciously employed as they may ensure longer treatment duration with novel anti-MM therapeutic agents, conferring superior response and survival in this difficult to treat MM subgroup. This also paves the path to further optimize dex dose in various anti-MM regimens, especially in these patients who are more likely to be intolerant to it. Disclosures Kumar: Skyline, Noxxon: Honoraria; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy; Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding.

Abstract Abstract 3053 Background: Patients with smoldering multiple myeloma (SMM) have a higher chance of progression to active MM than patients with monoclonal gammopathy of undetermined significance (MGUS). Since active MM remains incurable and since patients with SMM can have a long time to requiring treatment, observation remains an option for these patients. Bisphosphonates can prevent the bone complications of myeloma. The immunomodulatory (IMiD) drugs are well-tolerated and have documented anti-tumor activity in active MM. We hypothesized that treatment with the IMiD THAL and a bisphosphonate (ZLD) would prolong the time to progression (TTP) over the control arm of ZLD alone. This is the first report of this phase III trial of THAL/ZLD vs ZLD alone for patients with untreated SMM. Goals: The primary goal of this trial was to compare the TTP between patients treated with THAL/ZLD versus ZLD alone in asymptomatic MM. Secondary goals were progression rate at one year, response rate, duration of response, time to next therapy, and toxicity. Methods: Patients were required to have measurable disease as defined by either a serum monoclonal protein >1.0 g by protein electrophoresis or nephelometry or >200 mg of monoclonal protein in the urine on 24 hour electrophoresis or a measurable soft tissue plasmacytoma; >10% plasma cells as measured on the bone marrow aspirate, bone marrow biopsy, or labeling index; absolute neutrophil count >1500/μL; platelet count >100,000/μL; creatinine <2.0 mg/dL, and a performance status of 0, 1, or 2. Patients could not have symptomatic MM that required chemotherapy. The statistical plan was to accrue 120 eligible patients (60 per arm) over 4 years and after a minimum follow-up of 12 months the study would provide >90% power at a type I error rate of 0.05 to detect an increase in the median TTP from 12 months (ZLD) to 24 months (THAL/ZLD), and >80% power to detect an increase in median TTP from 12 to 21 months). Results: The study was activated in July 2003 and closed March 2009 due to slow accrual. Sixty-eight patients (35 Thal/ZLD; 33 ZLD) with a median age 63 years (range, 47–84) were randomized. The median TTP for Thal/ZLD versus ZLD was 2.4 years versus 1.2 years, respectively, P=0.02 one-sided log-rank. After adjusting for pre-specified stratification factors, the hazard ratio for TTP was 2.2 (one-sided p value = 0.01, univariate stratified Cox PH model) for ZLD compared to Thal/ZLD. 89% of patients on the Thal/ZLD arm were progression-free survival (PFS) at one year compared to 55% on ZLD alone (one-sided p<0.001, chi-square). Similar results were obtained (Table and Figures) when the CRAB (calcium, renal, anemia, bone) criteria were applied. Confirmed response was evaluated using the first 12 months of treatment. In the Thal/ZLD arm the response rate was 31% with a median duration of response of 5.1 years (95% CI: 1.9 - NA). There were no confirmed responses in the ZLD alone arm. The median overall survival has not been reached for either arm. In regards to toxicity, no grade 5 adverse events (AEs) have been reported. Thirty patients have reported grade 3+ AEs (17 Thal/ZLD; 13 ZLD, Fisher's exact p-value 0.47). Eight patients have reported grade 4 adverse events (5 Thal/ZLD; 3 ZLD, Fisher's exact p-value 0.71). Overall, only one grade 4 event was felt to be at least possibly related to study treatment – grade 4 neutropenia in Thal/ZLD. Conclusions: While the trial did not meet its planned accrual goals, there was a significant improvement in improved in outcomes in the Thal/ZLD arm compared to control (ZLD). Thal/ZLD produces anti-tumor responses that are quite durable with the median response duration of over 5 years. ZLD alone did not produce any anti-tumor responses. This study indicates that a non-chemotherapy approach can be effective in SMM and may be a useful strategy to test in future studies. Disclosures: Off Label Use: Thalidomide for smoldering myeloma. Lacy:Celgene: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Gertz:Celgene: Honoraria; Millennium: Honoraria.

Abstract Background: Retrospective analyses have demonstrated significantly improved survival for AYA ALL patients (pts) aged 16-21 years (yrs) when treated on pediatric versus adult U.S. NCI Cooperative group regimens where 2-yr event-free survivals (EFS) have been only 35-40%. The purpose of C10403, a large prospective US intergroup trial, was to evaluate the feasibility and effectiveness [with EFS as a primary endpoint), of treating AYA ALL pts (ages 16-39 yrs) using the standard arm of the successful Children's Oncology Group regimen (COG AALL0232) . Methods: Newly diagnosed AYA patients with B-precursor (B-ALL) or T-precursor (T-ALL) ALL were eligible to enroll on C10403. Burkitt type and Ph+ ALL were excluded. The regimen was identical to the Capizzi methotrexate arm of COG AALL0232 (Larsen E. JCO 2011; 29 suppl:3) and consisted of four intensive courses: remission induction, remission consolidation, interim maintenance, delayed intensification, and prolonged maintenance therapy. Pts with M2 marrow response (>5% but < 25% lymphoblasts) after remission induction received an extended remission induction course of therapy. Events were defined as induction failure (M3 [³25% blasts] day 29 of induction or M2 day 43 of extended induction), death, relapse, or second malignancy. Key correlative science studies in a subset of the total accrued population included assessment of Minimal Residual Disease (MRD) using quantitative real-time PCR of clonal IgH or TCR gene rearrangements as well as Low Density Microarray (LDA) assays designed to detect a previously validated gene expression profile (Harvey, R; ASH 2013, abstract 826) which can prospectively identify ALL pts with Ph-like (BCR-ABL1-like) ALL. Results: 318 pts were enrolled on C10403 from 11/2007 to 8/2012; 22 withdrew prior to therapy. Of 296 evaluable pts, the median age at diagnosis was 24 yrs (range: 17 to 39): 25% were 17-20 yrs, 53% were 21-29 yrs, and 22% were 30-39 yrs. The majority had B-ALL (76%) and were male ( 61%). Approximately 25% were non-Caucasian and 15% were Hispanic or Latino. 32% of pts were obese (BMI³30). There were 5 (2%) treatment-related deaths during protocol therapy: liver failure (n=2, both during induction), infection (1 in induction, 1 in consolidation), and ventricular arrhythmia (1 in induction). Overall, treatment toxicities were similar to those reported in the standard arm of COG AALL0232, with an increased thrombosis and early hyperbilirubinemia for C10403 pts, as reported previously (Advani A, ASH 2013, abstract 303). To date, 70 deaths have been reported and 87 pts remain on protocol therapy. With a median follow-up of 28 months for surviving pts, 105 events have been observed. The median EFS overall is 59.4 months (95% CI: 38.4 to NR) and the 2-yr EFS rate overall is 66% (95% CI: 60 – 72%) [Fig 1a] with similar 2-yr EFS rates for B and T- ALL pts (65%, and 68%). The 2-yr OS rate is 78% (95% CI: 72 – 83%)[Fig 1b], which is similar for B (78%, 95% CI: 72 – 84%) and T-ALL, (80%, 95% CI: 70 – 91%). These results allow rejection of the null hypothesis of this Phase II trial that the true median EFS is, at most, 32 months. In multivariable analysis of presenting clinical features, age > 20 years and initial WBC count ³ 30k/microliter were significantly associated with worse EFS and OS. Presence of MRD at day 28 following initiation of induction therapy and presence of a Ph-like gene expression signature were significantly associated with both worse EFS and OS. Notably, absence of detectable MRD noted in 22/58 [38%] evaluable pts at day 28 of induction was associated with 100% EFS (p=0.0006). The Ph-like like signature was detected in 28% of pts tested on C10403 and the 2 yr EFS for these patients was only 52%, compared to 81% for those without Ph-like disease (p = 0.04). Conclusions: This large prospective US adult intergroup trial (C10403) for pts 16-39 years old employing an intensive pediatric regimen demonstrates a significant improvement (compared to historical controls) in AYA EFS and OS and validates this approach for treatment of AYA with ALL by adult hematologists. The improved clinical outcomes and the predictive value of the correlative studies in this trial lay the foundation for the design of future trials, where incorporation of novel agents to eradicate MRD, and/or use of tyrosine kinase inhibitors to target the frequently detected Ph-like ALL in AYA pts may further improve survival for young adults with ALL. Figure 1a Figure 1a. Figure 1b Figure 1b. Disclosures Stock: Sigma-Tau: Membership on an entity's Board of Directors or advisory committees, Research Funding. Advani:Sigma Tau: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees. Liedtke:Onyx: Membership on an entity's Board of Directors or advisory committees. Larson:Novartis: Consultancy, Research Funding.

Abstract Background: Pomalidomide has demonstrated excellent activity in patients with relapsed, lenalidomide refractory, multiple myeloma (MM). Between November 2007 and March 2012, we enrolled 285 patients with relapsed MM on 5 sequential phase 2 trials; patients received pomalidomide at 2mg or 4 mg daily with weekly dexamethasone (Pom/dex). The approved dose of pomalidomide is 4 mg for 21 of 28 days. We wished to compare efficacy, tolerability and long-term outcomes between cohorts treated with 2 mg or 4mg daily continuously and 4mg daily for 21/28 days. Methods: After excluding two ineligible patients, 283 patients with lenalidomide refractory, relapsed MM from 5 sequential cohorts were analyzed. These patients were divided into 3 groups: Group1 received Pom 2mg for 28/28 day cycle (N= 69), Group 2 received Pom 4 mg for 28/28 day cycle (N= 95) and Group 3 received Pom 4mg for 21/28 day cycle (N= 119). All patients received oral dexamethasone given 40 mg daily on days 1, 8, 15, and 22. Response was assessed by the IMWG Uniform Response criteria. All patients received aspirin 325 mg daily for DVT prophylaxis or full dose anticoagulation. Results: The median age was 63 years (32-85); 35% were female. The median time from diagnosis was 53 months and the median number of prior regimens was 4. 127 (46%) had high-risk molecular markers. Prior therapies (% received) included lenalidomide (100%), thalidomide (46%), bortezomib (78%), autologous stem cell transplant (71%), and allogeneic transplant (4%). The median follow-up is 16.4 months (3.2-64.4). Forty eight percent are alive and 26% remain progression free; 15 patients are continuing to receive treatment. Frequency of AEs by groups are shown in Table 1. The most notable difference is grade 3+ neutropenia seen in 39% of group 1 and 56% and 57% of groups 2 and 3. Confirmed responses of PR or better were seen in 29% (group1), 35% (group2) and 24% (group3). Median duration of response (DOR) was 14.1 months (group1), 14.5 months (group2) and 10.2 months (group3). Median PFS was 5.5 months (group1), 6.9 months (group2) and 4.3 months (group3). Although the dose level cohorts were sequential rather than randomized, we compared OS between the dose levels in an exploratory manner. There was no significant difference in OS between dose levels (p=0.26). Median overall survival (OS) was 16.6 months (group1), 21.9 months (group2) and 16.0 months (group3). Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients Responses are durable. Response rates and overall toxicity are similar between the 2 mg and 4 mg doses. Neutropenia is more common in those receiving doses of 4mg daily or for 21/28 days compared to those receiving 2 mg daily. Table 1. All Grades Grade 3+ 2mg 28 Day 4mg 28 Day 4mg 21 Day 2mg 28 Day 4mg 28 Day 4mg 21 Day Anemia 68% 58% 74% 14% 15% 27% Lymphopenia 22% 51% 11% 16% 32% 8% Neutropenia 71% 82% 77% 39% 57% 56% Thrombocytopenia 51% 61% 63% 10% 9% 23% Leukopenia 59% 77% 72% 26% 38% 39% Pneumonia 7% 11% 12% 6% 7% 11% Fatigue 51% 65% 60% 9% 5% 8% Neuropathy 28% 32% 28% 0% 3% 0% Elevated Blood Glucose 10% 21% 8% 4% 6% 3% Pneumonitis 3% 2% 3% 3% 1% 1% VTE (Thrombosis) 3% 3% 3% 1% 3% 3% Secondary Malignancy 0% 2% 1% 0% 2% 1% Figure1. Kaplan Meier Overall Survival Curves Figure1. Kaplan Meier Overall Survival Curves Disclosures Lacy: Celgene: Research Funding. Fonseca:Medtronic, Otsuka, Celgene, Genzyme, BMS, Lilly, Onyx, Binding Site, Millennium, AMGEN: Consultancy, patent for the prognostication of MM based on genetic categorization of the disease. He also has sponsored research from Cylene and Onyx Other, Research Funding. Bergsagel:Novartis: Research Funding; Constellation Pharmaceutical: Research Funding; OncoEthix: Research Funding; MundiPharma: Research Funding. Stewart:Novartis: Consultancy; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Array BioPharma: Consultancy; Sanofi: Consultancy; Takeda Pharmaceuticals International Co.: Research Funding. Reeder:Millennium, Celgene, Novartis: Research Funding. Mikhael:Onyx: Research Funding; Celgene: Research Funding; Sanofi: Research Funding; Novartis: Research Funding.

Abstract Background: Pomalidomide is an immunomodulatory agent (IMiD®) that has been approved for treatment of relapsed and refractory multiple myeloma (MM). Combinations of IMiDs and proteasome inhibitors offer the potential for deeper and more durable responses due to enhanced efficacy. Preliminary results of a phase 1 study of twice weekly bortezomib with pomalidomide have been reported with promising results (Richardson, ASH 2012). This phase I/II trial was designed to evaluate the maximum tolerated doses (MTD) as well as safety and efficacy of the combination of pomalidomide, once weekly bortezomib and dexamethasone (PVD) in patients with relapsed, lenalidomide refractory, MM. Patients and methods: We included patients with relapsed MM who had 1-4 prior lines of therapy and were resistant or refractory to lenalidomide. In the phase I portion of the trial, dose level 1 consisted of pomalidomide 4 mg days 1-21 PO, bortezomib 1.0mg/m2 days 1,8,15, and 22 IV or SQ and dexamethasone 40 mg days 1,8,15, and 22 PO, given every 28 days. Bortezomib was increased to 1.3mg/m2 for dose level 2 and and was adopted for the phase 2 portion. The primary aim of the phase I cohort was to determine the MTD of the combination, and for the phase II cohort was to evaluate the confirmed response rate (PR, VGPR, or CR) in relapsed refractory MM. Response was assessed by the IMWG criteria and toxicity was graded using the CTCAE v4.0. Results: 50 patients were accrued between March 2012 and July 2014 (dose level (DL)1: 3, DL 2: 6, Phase II: 41). We describe results in 47 patients treated at MTD and phase II. Median age was 66, 51% were female and median time from diagnosis to study was 46 months (15-142). Twenty five percent had mSMART defined high-risk status. Median number of prior regimens was 3. All patients had prior lenalidomide, 68% had stem cell transplant, 17% received thalidomide, 56% had alkylators and 57% had bortezomib. With median follow up of 9 months, 72% remain progression free, 96% are alive and 66% remain on treatment. The most common AEs at least possibly attributable to the combination were anemia, fatigue, leukopenia and thrombocytopenia; however, the majority of these were grade 1-2. Grade ≥3 AEs (regardless of attribution) that occurred in at least 3 patients included neutropenia (29), leukopenia (15), lung infection (6), lymphopenia (8) dyspnea (3) and syncope (3). DVT/PE occurred in one patient. Among the 42 patients who were evaluable, confirmed responses (PR, VGPR, or CR) were seen in 34 (81%) including sCR (3), CR (5), VGPR (8), PR (18). Confirmed responses were seen in 9 of 11( 82%) high risk patients. Median progression free survival was 17.7 months (95%CI: 9.5-NA). Conclusions: PVD is a highly effective combination in patients refractory to lenalidomide with confirmed responses in over 80%. Weekly administration of bortezomib enhanced the tolerability and convenience of this regimen. Toxicities are manageable, mostly consisting of mild cytopenias with no significant neuropathy or DVT. PVD is a highly attractive option in patients with relapsed and refractory MM. Disclosures Lacy: Celgene: Research Funding. Lust:Senesco: PI Other. Fonseca:Medtronic, Otsuka, Celgene, Genzyme, BMS, Lilly, Onyx, Binding Site, Millennium, AMGEN: Consultancy, patent for the prognostication of MM based on genetic categorization of the disease. He also has sponsored research from Cylene and Onyx Other, Research Funding. Stewart:Celgene: Consultancy; Novartis: Consultancy; Array BioPharma: Consultancy; BMS: Consultancy; Millenium: Research Funding. Reeder:Millennium, Celgene, Novartis: Research Funding. Mikhael:Onyx: Research Funding; Celgene: Research Funding; Sanofi: Research Funding; Novartis: Research Funding.

Abstract Sorafenib is an oral multikinase inhibitor that blocks the autophosphorylation and activation of a number of kinases including the FLT3 tyrosine kinase with an internal tandem duplication mutation (FLT3-ITD). Sorafenib has activity against AML with FLT3-ITD mutations as a single agent in the setting of post-transplant relapse and in combination with chemotherapy for newly diagnosed AML. Historical Cancer and Leukemia Group B results using standard chemotherapy for older patients (pts) with FLT3-ITD have demonstrated a complete remission (CR) rate of 67%, median survival of 0.8 yrs, and 1-yr overall survival (OS) of 30% (Whitman et al., Blood 2010). More recently, sorafenib was demonstrated to significantly prolong event-free (EFS) and disease-free survival (DFS) of younger adults irrespective of FLT3 mutation status (Rollig, et al., ASH 2014). We hypothesized that the addition of sorafenib to induction and post-remission therapy would improve the overall survival of older pts with FLT3-mutated AML. The Alliance for Clinical Trials in Oncology conducted a multicenter, single-arm phase 2 study in pts ≥ 60 years old with AML and either a FLT3-ITD or a point mutation in the activation loop of the kinase domain (FLT3-TKD). Subjects with PML-RARA, core-binding factor AML or who had received prior treatment for AML were excluded. Induction chemotherapy consisted of cytarabine 100 mg/m2 CIVI on days 1-7 and daunorubicin 60 mg/m2 IV on days 1-3 (7+3) with oral sorafenib 400 mg bid on days 1-7. Those not achieving a hypoplastic bone marrow on day 14 were to receive a second cycle of cytarabine and daunorubicin (5+2) plus sorafenib 400 mg bid on days 1-7. Post-remission therapy consisted of intermediate-dose cytarabine 2 g/m2 on days 1-5 with sorafenib 400 mg bid on days 1-28 for 2 cycles followed by maintenance sorafenib 400 mg bid for 12 28-day cycles. The primary endpoint of the study was 1-yr OS. With a sample size of 39 FLT3-ITD patients and type I error rate of 10%, this design provided 90% power to distinguish between true 1-yr OS rate of 50% compared to our historical rate of 30% for the FLT3-ITD pts. A total of 474 pts were screened for FLT3 mutations though a central laboratory. FLT3 mutations were identified in 83 subjects (17.5%). Fifty-four pts with a median age of 67 years (60.3-82.7) were enrolled, including 39 with FLT3-ITD (71%) and 15 with FLT3-TKD (29%). All pts have now completed protocol treatment. Of the 54 pts, 37 achieved a CR or CRi (69%). The 30-day induction mortality was 9% with no additional deaths occurring between days 30-60. With a median follow up of 28.3 months, the observed 1-yr OS (95% CI) was 62% (45-78) for the FLT3-ITD pts and 71% (42-92) for the FLT3-TKD pts. The median DFS and OS was 12.5 mo (7.7-17.4) and 15.0 mo (10.4-20.1) respectively in the FLT3-ITD group and 9.0 (1.6-NA) and 16.2 mo (5.0-NA) for the FLT3-TKD group. For all subjects, the 2-yr OS was 28% (17-43) and DFS was 27% (15-46). There were no treatment-related deaths during consolidation or maintenance. For pts receiving sorafenib maintenance, the most commonly reported related adverse events were Grade 1 diarrhea, fatigue, transaminitis, and Grade 2 palmar-plantar erythodyesthesia. The mean plasma inhibitory activity (PIA) for FLT3 was 94% (n=25) on day 6 of induction, 93% (n=15) on day 15 of consolidation and 99.2% (n=6) on day 15 of maintenance demonstrating robust inhibition of FLT3 in vivo. This study represents the first prospective clinical trial for older adults with AML targeting a specific mutational profile within the US cooperative group setting. The study met the primary endpoint demonstrating that the addition of sorafenib to chemotherapy for FLT3-ITD AML improves the survival of older adults more than doubling the 1-yr OS compared to historical controls (62% vs 30%, p <0.0001). Disclosures Uy: Novartis: Research Funding. Off Label Use: Sorafenib for AML. DeAngelo:Novartis: Consultancy; Ariad: Consultancy; Bristol Myers Squibb: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Incyte: Consultancy; Agios: Consultancy; Celgene: Consultancy. Stock:Gilead: Membership on an entity's Board of Directors or advisory committees. Byrd:Acerta Pharma BV: Research Funding. Stone:Celator: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; Roche/Genetech: Consultancy; Amgen: Consultancy; Karyopharm: Consultancy; Abbvie: Consultancy; AROG: Consultancy; Merck: Consultancy; Sunesis: Consultancy, Other: DSMB for clinical trial; Novartis: Research Funding; Juno: Consultancy; Agios: Consultancy. Larson:Bristol-Myers Squibb: Consultancy; Pfizer: Consultancy; Ariad: Consultancy, Research Funding; Novartis: Consultancy, Research Funding.

Abstract Purpose: Clinical trials in APL have generally reported similar outcomes for children and adults. However, sub-group analysis of pediatric patients treated on 2 consecutive trials of the European APL group demonstrated that children <5 years (yr) had an increased risk of relapse (Bally et al., JCO, 2012). Here we report the effect of age < 5 yr on outcome for the North American Intergroup Study C9710. Methods: Outcomes were compared among young children (age <5 yr, n=16) to those of older age (5-12 yr, n=25 and 13-18 yr, n=45) enrolled on C9710. Treatment on C9710 included induction with daunorubicin, cytarabine and ATRA followed by two consolidation cycles with daunorubicin and ATRA and maintenance for one year with ATRA +/- mercaptopurine and methotrexate. Patients of age ≥15 yr were randomized to receive or not receive two 5-week cycles of arsenic trioxide (ATO) before the chemotherapy consolidation. However, analysis in this study of young children compared to those of older age was restricted to patients who did not receive ATO. Results: Clinical remission (CR) rates were similar between the 3 age groups (age <5 yr= 88%, age 5-12 yr= 80%, age 13-18 yr= 82%; P=0.93). Overall survival (OS) Kaplan-Meier estimates were not significantly different (log rank P=0.84), and 5 yr OS rates were 77% (age <5 yr), 80% (age 5-12 yr), and 84% (age 13-18 yr). Similarly, event-free survival (EFS) Kaplan-Meier estimates were not significantly different (log rank P=0.48), and 5 yr EFS rates were 56% (age <5 yr), 47% (age 5-12 yr), and 59% (age 13-18 yr). Young children did not have a higher relapse rate (5-yr cumulative incidence of relapse by age: <5 yr=29%, 5-12 yr=49%, 13-18 yr=29%). Conclusions: Results of this intergroup trial demonstrate that ATRA administration during induction, consolidation and maintenance leads to CR rates >80% and 5 yr OS rates >75%. These results are superior to recently published results of pediatric non-APL acute myeloid leukemia and confirm results from the prior APL intergroup trial (INT0129) that demonstrated that ATRA in induction and/or maintenance significantly improved outcomes for pediatric APL (Gregory et al., Ped Blood and Cancer, 2009). Our sub-group analysis showed no association of age with outcomes in children treated with this regimen. Disclosures Off Label Use: Daunorubicin- labeled for use in AML for adults and for pediatric ALL (not pediatric AML) Arsenic Trioxide- labeled for use in relapsed/refractory APL (not de novo APL) Mercaptopurine and Methotrexate- labeled for use in pediatric ALL (not APL).

Abstract Purpose: Recent studies have demonstrated differential outcomes for adolescents and young adults (AYAs) vs. children treated for acute myeloid leukemia. Here we analyze outcomes by age group for APL patients treated on the North American Intergroup Study C9710. Methods: Patient characteristics and outcomes were compared between children (<15 yr, n=55) vs. AYAs (15-31 yr, n=42). To control for differences in treatment center, only young adults registered at Children’s Oncology Group (COG) treatment sites were included. Treatment included induction with daunorubicin, cytarabine and ATRA. All patients (pts) received two consolidation cycles with daunorubicin and ATRA and maintenance for one year with ATRA +/- mercaptopurine and methotrexate. Pts ≥15 yr were randomized to an additional two cycles of arsenic trioxide (ATO). Sub-group analysis was also performed to exclude pts ≥15 yr who received ATO and thus compare only patients <15 yr vs. ≥15 yr who had not received ATO. Results: Children and AYAs had similar characteristics of gender, race/ethnicity, Sanz risk grouping and M3v histology. Among all pts enrolled at COG sites on the study, complete response (CR) rates were similar (<15yr =85% vs. ≥15yr =81%, P=0.59). AYAs had improved 5 yr disease-free survival (DFS) from time of CR compared to younger pts (<15 yr =47% vs. ≥15 yr =70%, log rank P=0.05), and there was a trend toward difference in 5 yr event-free survival (EFS) (<15 yr =46% vs. ≥15 yr =63%, log rank P=0.13). Overall survival (OS) at 5 years was not significantly different (<15 yr =82% vs. ≥15 yr =75%, log rank P=0.47). Twenty-three of 42 pts ≥15 yr received ATO consolidation cycles, which may have contributed to their improved DFS and EFS. Thus, we analyzed outcomes by removing from the analysis patients ≥15 yr who received ATO consolidation cycles, and compared pts <15 yr who did not receive ATO (n=55) to pts ≥15 yr who were randomized to no ATO (n=19). CR rates were again similar (<15 yr =85% vs. ≥15 yr no ATO =84%, P=1.0). There was no significant difference in other outcomes including 5-yr DFS from time of CR (<15 yr =47% vs. ≥15 yr no ATO =63%, log rank P=0.31), 5-yr EFS (<15 yr =46% vs. ≥15 yr no ATO=53%, log rank P=0.89), or 5-yr OS (<15 yr =82% vs. ≥15 yr no ATO=79%, log rank P=0.78). Conclusions: The C9710 study demonstrated improved EFS, DFS and OS among adult patients receiving ATO consolidation compared to those who did not receive ATO (Powell et al., Blood, 2010). The current analysis of results for AYAs versus younger pediatric pts showed improved DFS among the whole AYA cohort (of which 55% received ATO consolidation) compared to pts <15 yr (of which 0% received ATO). When the analysis was restricted to AYA pts not receiving ATO, however, the results of this intergroup APL trial showed similar CR, DFS, EFS and OS for AYAs and younger pts. Thus, unlike other subtypes of AML, APL appears to have a consistent response across the pediatric and AYA age groups. The most recent COG clinical trial in APL is now evaluating whether pediatric patients can also benefit from ATO consolidation. Disclosures Off Label Use: Daunorubicin- labeled for use in AML for adults and for pediatric ALL (not pediatric AML) Arsenic Trioxide- labeled for use in relapsed/refractory APL (not de novo APL) Mercaptopurine and Methotrexate- labeled for use in pediatric ALL (not APL).

Abstract Abstract 201 Background: Pomalidomide at doses of 2 or 4 mg/d has demonstrated excellent activity in patients with relapsed multiple myeloma (MM). Between November 2007 and March 2012, we opened 6 sequential phase 2 trials and treated 345 patients with relapsed MM with pomalidomide at differing doses with weekly dexamethasone (Pom/dex). Results of 164 of these patients have been previously published. Here we describe long term follow up of these patients as well as results of an additional 181 patients with relapsed MM treated with the Pom/dex regimen. Methods: The six cohorts consisted of: Cohort 1 (N=60): relapsed MM with 1–3 prior regimens, 2 mg dose; Cohort 2 (N=34): lenalidomide (LEN) refractory, 2 mg dose; Cohort 3 (N=35): BZ)/LEN refractory, 2 mg dose; Cohort 4 (N=35): BZ/LEN refractory, 4 mg dose; Cohort 5 (N=60) LEN refractory, 1–3 prior regimens, 4 mg dose; and Cohort 6 (N=120) LEN refractory, 4 mg dose. Pomalidomide was given orally 2 mg daily or 4mg daily on days 1–28(cohorts 1–5) or 1–21 (cohort 6) of a 28-day cycle with oral dexamethasone given 40 mg daily on days 1, 8, 15 and 22. Response was assessed by the International Myeloma Working Group Uniform Response criteria. All patients received aspirin 325 mg daily for deep venous thrombosis (VTE) prophylaxis or full dose anticoagulation. Results: A total of 345 patients were enrolled across all 6 cohorts. One patient was ineligible and excluded from analysis. The median age was 64 years (32–88). The median time since diagnosis was 53 months. The median number of prior therapies was 3 (1–14). 147 (44%) had high-risk molecular markers by mSMART criteria. Prior therapies consisted of thalidomide 52%, lenalidomide 87%, bortezomib 75%, autologous stem cell transplant 70% and allogeneic transplant 3%. The median follow-up is 10.4 months (5.4–34 months). Sixty-seven percent are alive and 32% remain progression free. 46 patients are continuing to receive treatment. The most common toxicities (grade 3 or higher) were neutropenia (31%), anemia (16%), thrombocytopenia (12%), pneumonia (8%) and fatigue (8%). VTE was seen in 10 patients (3%). Outcomes are shown in Table 1. Across all 6 cohorts confirmed responses of partial response (PR) or better were seen in 34%. The response rate in all patients with mSMART high risk status was 30.6%. Responses and duration of response (DOR) in those with high risk molecular markers include: 17p– 19 of 56 (34%) DOR 8.2 months; t(4;14) 6 of 24 (25%) and DOR 4.8 months; t(14;16) 7 of 11(64%) and DOR 9.5 months; deletion 13 by cytogenetics 13 of 37 (35%) with DOR 8.2 months. In a multivariate analysis, only LDH > ULN, number of prior regimens, and prior BZ therapy were predictive of a shorter TTP and factors associated with a poor OS following initiation of pomalidomide therapy included B2M > 5.5, LDH > ULN,number of prior regimens, and prior BZ therapy. Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients and those with high risk molecular markers. Remissions are durable. Response rates and toxicity are similar between the 2 mg and 4 mg doses. Disclosures: Lacy: Celgene: Research Funding. Stewart:Celgene: Consultancy, Honoraria. Reeder:Celgene: Mayo Clinic receives funding from Celgene to support clinical trials Other, Research Funding.